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| author | alc <alc@FreeBSD.org> | 2005-04-21 23:07:20 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2005-04-21 23:07:20 +0000 |
| commit | b459bdba219f3fa62232f821fc325ce4a3f05974 (patch) | |
| tree | 6c9382005f6d2d9ebd16979efd2a63cfa990c571 /lib/libc/i386/string | |
| parent | 2b9aae1b7a6e7fb07dfaaa35a34911449d807dea (diff) | |
| download | FreeBSD-src-b459bdba219f3fa62232f821fc325ce4a3f05974.zip FreeBSD-src-b459bdba219f3fa62232f821fc325ce4a3f05974.tar.gz | |
Eliminate an unpredictable branch from bcmp().
Reviewed by: bde
Diffstat (limited to 'lib/libc/i386/string')
| -rw-r--r-- | lib/libc/i386/string/bcmp.S | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/lib/libc/i386/string/bcmp.S b/lib/libc/i386/string/bcmp.S index 60ece4f..aa6a6ab 100644 --- a/lib/libc/i386/string/bcmp.S +++ b/lib/libc/i386/string/bcmp.S @@ -43,7 +43,6 @@ ENTRY(bcmp) pushl %esi movl 12(%esp),%edi movl 16(%esp),%esi - xorl %eax,%eax /* clear return value */ cld /* set compare direction forward */ movl 20(%esp),%ecx /* compare by words */ @@ -56,9 +55,9 @@ ENTRY(bcmp) andl $3,%ecx repe cmpsb - je L2 - -L1: incl %eax -L2: popl %esi +L1: + setne %al + movsbl %al,%eax + popl %esi popl %edi ret |
